1. Field of the Invention
The present invention relates to methods and apparatus for drilling into the subterranean, and to methods for modifying drilling equipment. In another aspect, the present invention relates to methods and apparatus for drilling for hydrocarbons, and to methods for modifying existing hydrocarbon drilling equipment. In even another aspect, the present invention relates to top drive drilling apparatus. In even another aspect, the present invention relates to an improved top drive having a passage through which may be passed drilling tubulars, and to methods of drilling utilizing such a top drive that allows for passage of drilling tubulars through the top drive without moving the top drive aside, thus providing for increased efficiency and safety in handling drilling tubulars. In addition, the present invention relates to methods of modifying existing drilling equipment to utilize such a top drive.
2. Description of the Related Art
Until recent times, conventional well drilling systems most commonly utilized a rotary table drilling system requiring the use of a rotary table, kelly and kelly bushing.
In such conventional drilling systems, the drill pipe string, an assembly or xe2x80x9cstringxe2x80x9d of drill pipe connected to the drill bit at one end, is rotated in the well bore by a kelly connected at the other end. The kelly is rotated by a rotary table.
In operation, once rotary table drilling has advanced one pipe length, drilling is halted, the pipe string is de-coupled from the kelly, another pipe length is added to the pipe string, the string is re-coupled to the kelly, and then drilling is resumed.
Thus, one limitation of rotary table drilling is that it only allows for drilling in increments of single pipe lengths (approximately 31 feet/9.4 meters).
The top drive drilling unit was developed to overcome this single pipe length limitation, and allows for drilling an entire stand of drill pipe, which consists of a multiple of single lengths of drill pipe connected together. Typically stands consists of three pipe lengths (approximately 93 feet/28.3 meters). Essentially, the top drive rotates the drill string from the top of the string as opposed to earlier methods of drilling with a rotary table and kelly at the rig floor.
While the concept of using a top drive unit, also referred to as overhead rotary drilling, derrick drillers, and overhead power swivels, on drilling rigs dates back to the 1920""s, practical systems date only from the 1980""s. Many of the early conventional top drive units suffer from an inability to efficiently handle drilling tubulars (pipe or tubing). Specifically, many conventional top drive units cannot easily or efficiently accommodate connection and disconnection of pipe lengths, and the moving and handling of stands of drill pipe.
It was in the 1980""s that commercial top drive systems complete with pipe handler (breakout wrench, lift tilt, overdrill provisions and inside well control) were developed that overcame some of the previous limitations. These systems allowed for continuous drilling of stands of drill pipe, and for circulating and reaming the hole during the procedures of tripping in and tripping out.
However, when adding a new stand of drill pipe by use of many presently available conventional top drive systems, it is necessary for the top drive to break out of the drill string, and tilt out to align and stab the stand of drill pipe in the mouse hole. This xe2x80x9ctilting outxe2x80x9d causes the stand of drill pipe, to sway when the stand of pipe is lifted. The swaying movement is unsafe and can cause injury or damage if not controlled.
In a conventional tripping out cycle, an elevator attached to a top drive unit is lowered and attached to the top of the drill string. The drill string is raised up so that the stand of pipe to be broken out is above the rig floor and slips are set to secure the string. After a break out tool breaks out the stand of pipe, the top drive elevator must then hand off, or transfer, the stand of pipe to a derrick hand or a mechanical pipe handler for racking the stand in the derrick. There are many conventional techniques and methods for doing this step, yet these methods are generally awkward since the conventional top drive unit blocks access to the stand from above, thus not allowing supporting and lifting the stand from above. Due to the awkwardness of transferring the stand of pipe, this step can be dangerous and unsafe if the transfer is not carried out in a skillful and careful manner. Only after the drive elevator transfers the stand of drill pipe is the conventional top drive unit available to be lowered back down to the drill floor.
The art is crowded with patents relating to drilling of wells.
U.S. Pat. No. 4,437,524 issued Mar. 20, 1984, to Boyadjieff et al, discloses a well drilling apparatus designed to eliminate the need for a rotary table, kelly and kelly bushing, and includes a drilling unit which is shiftable between a drilling position in vertical alignment with a mousehole, and an inactive position.
U.S. Pat. No. 4,449,596 issued May 22, 1984, to Boyadjieff, discloses a top drive well drilling system that includes pipe handling equipment that facilitates the making and breaking of connections to the drill string during the drilling cycle.
U.S. Pat. No. 4,458,768 issued Jul. 10, 1984, to Boyadjieff, discloses a top drive well drilling system having a drilling unit shiftable to various positions, wherein the shifting movement is accomplished by means of a structure that guides the unit for movement along predetermined paths.
U.S. Pat. No. 4,605,077 issued Aug. 12, 1986, to Boyadjieff, discloses a top drive drilling system having a motor which is connected to the upper end of the drill string and moves upwardly and downwardly therewith.
U.S. Pat. No. 4,625,796 issued Dec. 2, 1986, to Boyadjieff, discloses an apparatus comprising a stabbing guide and a back-up tool, wherein the apparatus can function in aligning an additional length of pipe with the upper end of the drill string and thereby facilitates the controlled stabbing of pipe length for addition into the top of a drill string.
U.S. Pat. No. 4,667,752 issued May 26, 1987, to Berry et al, discloses a top head drive well drilling apparatus with a wrench assembly and a stabbing guide, wherein the wrench assembly is mounted on the drive unit and the stabbing guide is mounted on the wrench assembly.
U.S. Pat. No. 5,501,286 issued Mar. 26 1996, entitled to Berry, discloses and apparatus and method for displacing the lower end of a top drive torque track suspended from a derrick wherein a drive unit is disconnected from the drill string and suspended from the torque track. The top drive suspended from the torque track can then be moved away so as not to interfere with the addition or removal of drill string sections.
U.S. Pat. No. 5,755,296 issued May 26, 1998, to Richardson et al, discloses a portable top drive comprising a self-contained assembly of components necessary to quickly install and remove a torque guide and attendant top drive unit in a drilling rig mast.
In spite of the numerous modifications made in drilling apparatus, the current methods and apparatus for drilling and handling drill pipe are still awkward and many of the systems require that the top drive unit, or a portion thereof, tilt out for connecting to the next stand of drill pipe, as well as special methods or mechanisms for the top drive unit, or a portion thereof, to tilt out.
Due to the awkwardness and the manner in which drilling tubulars are handled there exists a need for a safer way to handle drilling tubulars when drilling and tripping.
Also, a significant amount of time is needed to handle stands of pipe when drilling and tripping. More efficient methods of handling drilling tubulars during drilling and tripping would also lower overall drilling costs.
Thus, there exists a need in the art for methods and apparatus for drilling the subterranean, and to methods and apparatus for modification of existing drilling equipment.
There exists another need in the art for methods and apparatus for drilling hydrocarbon wells, and to methods and apparatus for modification of existing hydrocarbon well drilling equipment.
There exists even another need in the art for improved methods and apparatus for drilling hydrocarbon wells.
There exists still another need in the art for improved methods and apparatus for drilling hydrocarbon wells that overcome one or more of the deficiencies of the prior art.
There exists yet another need in the art for methods and apparatus for drilling wells, not requiring tilt out of the top drive unit to connect to the next stand of pipe.
There exists still another need in the art for methods and apparatus for drilling wells, that provides for increased safety for operators and workers when drilling.
There exists even still another need in the art for methods and apparatus for drilling wells, that reduces the amount of time devoted to adding and removing stands of pipe to the drill string.
These and other needs in the art will become apparent to one of skill in the art upon review of the specification, including the drawings and claims.
It is an object of the present invention to provide for methods and apparatus for drilling the subterranean, and to methods and apparatus for modification of existing drilling equipment.
It is another object of the present invention to provide for drilling hydrocarbon wells, and to methods and apparatus for modification of existing hydrocarbon well drilling equipment.
It is even another object of the present invention to provide for improved methods and apparatus for drilling hydrocarbon wells.
It is still another object of the present invention to provide for improved methods and apparatus for drilling wells, which overcome one or more of the deficiencies of the prior art.
It is yet another object of the present invention to provide for drilling wells, not requiring tilt out of the top drive unit to connect the next stand of pipe.
It is also another object of the present invention to provide for drilling wells, that provides for increased safety for operators and workers when drilling.
It is even another object of the present invention to provide for drilling wells, that reduces the amount of time devoted to adding and removing stands of pipe to the drill string.
These and other objects of the present invention will become apparent to one of skill in the art upon review of the specification, including the drawings and claims.
Specifically, one or more of the following embodiments or other possible embodiments of the present invention are believed to represent an advancement in the art and/or are believed overcome one or more of the disadvantages of current drilling systems and provide a top drive system that (1) is more simple and safe than conventional systems; (2) reduces the awkwardness of handling drill pipe; (3) eliminates the need for a top drive unit to tilt out; (4) reduces the time required for the tripping in cycle; (5) reduces the time required for the tripping out cycle; and/or (6) reduces the total time required for the drilling procedure.
According to one embodiment of the present invention there is provided a drilling apparatus. The drilling apparatus comprises a main body structure or top drive and a drill string drive mechanism. Extending vertically through the main body structure is a main body passage. Positioned within the main body passage is the drill string drive mechanism which is rotatable in relation to the main body. Extending through the drive mechanism is a mechanism passage which is adapted to allow travel of drilling tubulars through the passageway. The drive mechanism is also adapted to be driven by a motor or plurality of motors and is further adapted to drive a drill string.
According to another embodiment of the present invention there is provided a drilling apparatus comprising a vertically extending tower that supports a main body structure having a main body passage extending therethrough. The main body comprises a drill string drive mechanism that is rotatably positioned within the main body passage and is rotatable in relation to the main body. Extending through the drill string drive mechanism is a mechanism passage adapted to allow travel of drilling tubulars through the passageway. The drive mechanism is adapted to be driven by a motor or plurality of motors, and is also adapted to drive a drill string.
According to even another embodiment of the present invention there is provided a drilling apparatus comprising a hollow core stem which has a first end, a second end, and a connecting member. The connection member is positioned between the first and second ends, and is adapted for connection to a drive mechanism. The first end of the core stem is adapted for connection to a drill string, while the second end is adapted for connection to a mud line assembly.
According to still another embodiment of the present invention there is provided a drilling apparatus comprising a vertically extending tower supporting a main body. Positioned to the main body is a drill string drive mechanism that is rotatable by one or more motors. Extending through the drill string drive mechanism and the main body structure is a main body passage. Positioned in the mechanism passage is a hollow core stem (which is removable or moveable from the main body passage) comprising a connecting member which rotatably connects the core stem to the drive mechanism. The mechanism passage can be adapted to allow travel of drill pipe therethough by moving or removing the hollow core stem from the mechanism passageway. The core stem further comprises a first end which extends into the mechanism passage and is positioned for connection to a drill string, and a second end adapted for connection to a mud line assembly. Also provided is an auxiliary hoisting system for handling and racking drilling tubulars, and a main hoisting system for providing vertical movement of the main body in relation to the tower.
According to yet another embodiment to the present invention there is provided a well drilling apparatus comprising a top drive assembly, a drilling fluid line assembly, and a hollow core stem. The top drive assembly comprises a main body defining a main body passage extending therethrough, and a drive mechanism defining a drive mechanism passage through the main body passage, wherein the drive mechanism is rotatably positioned within the main body passage, and wherein the drive mechanism passage is adapted to allow travel of drill pipe therethough. The drilling fluid line assembly comprises a drilling fluid line connector. The hollow core stem defines a core stem passage therethough, and is removably positioned within the drive mechanism passage. The core stem comprises a first end which extends into the drive mechanism passage and is adapted for connection to a drill string, and a second end which is connected to the drilling fluid line connector. In a preferred embodiment, the second end of the core stem and the drilling fluid line connector are rotatable relative to each other. In a more preferred embodiment, the second end of the core stem swivels in relation to the drilling fluid line connector. In addition, the core stem is adapted to be rotated by the drive mechanism and to drive rotation of the drill string.
According to even still another embodiment of the present invention there is provided a method of preparing drill pipe or a stand of pipe for a drilling operation comprising the step of connecting a drill pipe or stand of pipe to a hollow core stem. The hollow core stem comprises a connecting member adapted for connecting the core stem to a drive mechanism, a first end adapted for connection to a drill string, and a second end adapted or connection to a mud line assembly.
According to even yet another embodiment of the present invention there is provided a method for drilling a well comprising a first step of passing a drill pipe through a mechanism passage of a drilling apparatus. The drilling apparatus comprises a main body and a drill string drive mechanism. Extending through the main body is a main body passage in which there is rotatably positioned a drill string drive mechanism which is rotatable in relation to the main body. The drive mechanism has a mechanism passage extending through it that is adapted to allow travel of drilling tubulars therethrough. The drive mechanism is adapted to be driven by a motor or plurality of motors. The drive mechanism is also adapted to connect and drive the hollow core stem and the hollow core stem is adapted to connect to and drive the drill string. The method further comprises the steps of connecting drill pipe to the drill string, connecting the drill string to the drive mechanism, rotating the drill string into the well hole, and disconnecting the drill string and the drive mechanism.
According to still yet another embodiment of the present invention there is provided a method of disconnecting a portion of a drill string positioned in a well bore. The drill string has at least two portions of drill pipe positioned in the well bore. The method comprises lifting a portion of drill string from the well bore, passing the portion through a passage extending through a main body or top drive, and disconnecting the portion from the drill string.
According to even yet another embodiment of the present invention there is provided a method for adding drill pipe to a drill string. The method comprises passing drill pipe or stand of pipe to be added to the drill string through a passage extending through a main body or top drive, and connecting the drill pipe to the drill string.
According to yet even still another embodiment of the present invention there is provided a well drilling apparatus comprising a top drive assembly, a moveable part, a drilling fluid line and a drill string. The top drive assembly defines a top drive assembly passage extending therethrough, wherein said top drive assembly passage is adapted to allow travel of drill pipe therethrough. The moveable part is removably positioned within said top drive assembly passage, wherein said moveable part comprises a first end and a second end, and wherein said moveable part is rotatable by said top drive. The drilling fluid line is connected to said first end of said moveable part and the drill string is connected to said second end of said moveable part, wherein rotation of said moveable part by said top drive drives rotation of said drill string.
According to even still yet another embodiment of the present invention there is provided a method for modifying a drilling apparatus. The apparatus comprises a tower supporting a top drive through which drill pipe cannot pass. The method comprises removing the top drive from the tower, and placing a second top drive on the tower. Extending through the second top drive is passage through which drilling tubulars can be passed.
These and other embodiments of the present invention will become apparent to those of skill in the art upon review of this specification, including its drawings and claims.